package com.can.add;

import java.util.concurrent.Semaphore;
import java.util.concurrent.TimeUnit;

public class SemaphoreDemo {
    public static void main(String[] args) {
        //线程数量：停车位！限流！
        Semaphore semaphore = new Semaphore(3);
        for (int i = 1; i <= 6; i++) {
            new Thread(()->{
                //acquire()都会阻塞
                try {
                    semaphore.acquire(); // 得到
                    System.out.println(Thread.currentThread().getName()+"抢到车位");
                    TimeUnit.SECONDS.sleep(2);//挺两秒
                    System.out.println(Thread.currentThread().getName()+"离开车位");
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }finally {
                    semaphore.release();  //release() 释放

                }
            },String.valueOf(i)).start();
        }
    }
}
